Skiff That Bombed U.S. Destroyer Now Said to Have Moved In Alone

In the moments before it exploded, tearing a ragged hole in the destroyer Cole moored in Yemen, a white motorized skiff circled around the ship's bow and slowly skirted along its portside. Two men aboard the skiff nonchalantly waved to armed sailors standing watch on the Cole's deck, and the sailors waved back, officials said today in a new account of the attack.

The officials said the small boat had not been part of a flotilla helping the Cole moor to a refueling station in Aden on the morning of Oct. 12, contradicting initial Pentagon reports that its involvement in harbor operations enabled the attackers to avoid suspicion, and raising new questions about security on deck.

In fact, the Cole was already moored and taking on fuel -- with many of its crew members relieved from duty on deck -- when the skiff approached, according to senior officials who have pieced together an account of the events that morning.

Even so, the skiff's presence did not raise alarms among the sailors on watch. The crew was used to seeing curious boaters come up for a closer look whenever the Cole, one of the world's most advanced warships, sailed into port anywhere. At least some of those aboard assumed it must have been part of the mooring flotilla even though that operation had concluded, these officials said.

At 11:18 a.m. local time, or 4:18 a.m. Eastern time, the skiff reached the midpoint of the Cole, pulled within a few feet of the hull and, with the two men aboard standing up, erupted with the force of 500 pounds of explosives that had been ''shaped'' to concentrate the blast directly into the destroyer.

''It came around the side and came up in a slow manner,'' a senior government official who has reviewed witnesses' accounts said today. ''The guys in the boat waved at the Cole. There was nothing unusual; it was the way other boats have approached in port. They went putt-putt-putt along the side and then lit up.''

Eight days after the attack on the Cole killed 17 sailors, this clearer and significantly revised account of the bombing is beginning to emerge, according to administration officials, Navy commanders and some of those aboard the Cole that day.

Now that the last of those killed have been removed from the Cole, the new details have thrown a spotlight on the security precautions aboard the destroyer. They are also affecting the direction of the investigation, pointing to a strike that, one official said, could not have been carried out by known Yemeni terrorist cells without significant support from outside.

American investigators have completed field tests on residue found on the Cole, and one of the tests showed evidence of C-4, a powerful plastic explosive, two officials here said. However, the investigators do not believe the preliminary tests are conclusive and have brought samples to the United States for further analysis, they added.

Plastic explosives like C-4 are expensive and relatively difficult for terrorist groups to obtain.

The Navy announced today that in the initial confusion and overriding concern for the lost and wounded sailors, its commanders had misstated some of the details of the Cole's activities on the day of the attack. The Cole had in fact arrived in the port earlier in the morning, thrown its first mooring line over by 8:50 a.m. and completed mooring by 9:30. About 10:30 it began refueling and had been doing so for nearly 40 minutes when the skiff exploded at 11:18 -- an hour earlier than initially reported.

The revised timing is significant because it contradicts first reports that the attackers were involved in the mooring operation, or had infiltrated it and, having blended in, did not appear suspicious. In fact, the small fiberglass skiff, packed with explosives, was not supposed to be that close to the Cole at that time and yet still raised no alarms, the officials said, raising questions about the crew's security procedures as the destroyer was refueling in a port considered dangerous.

A senior Navy official said the ship's captain, Cmdr. Kirk S. Lippold, had reported by telephone to commanders in the region in the hours after the attack that the crew believed the skiff had been involved in mooring operation, suggesting the mooring was still under way. ''Now the question will be, why did they think that?'' the official said.

In addition to the criminal investigation in Yemen, the Navy and the Department of Defense have begun their own inquiries into what happened. Questions about the security procedures aboard the Cole and in the port will be a primary focus, officials have said.

The sequence of events outlined by officials today supports initial eyewitness accounts -- reported immediately after the blast -- that the skiff had approached the Cole alone and unchallenged, not as part of the mooring operation. That also supports reports by Yemeni authorities that the skiff had been launched from a trailer beneath a bridge in Little Aden, about six miles from where the Cole moored to the refueling station.

However, Yemeni officials have repeatedly said the boat seen launched that morning was a rubber dinghy, while American officials say the boat carrying the bomb was made of fiberglass.

Navy officials argued that the new details did not change the fundamental facts of the case, saying the Cole's sailors had no reason to suspect the skiff and could have done little to stop it. ''If a boat doesn't speed in and come right at you, how do you determine hostile intent?'' a senior officer said.

The unthreatening behavior of the two men -- and the fact the skiff was not unlike other boats plying the harbor -- evidently put the Cole's guards at ease. Still, the skiff raised enough concern by its actions that, according to the officials, the sailors aboard closely tracked it as it made its way and watched as the two men stood moments before the blast.

American warships entering any port -- especially one, like Aden, that is considered potentially dangerous -- have clear security guidelines. In this case, the officials said, the Cole was operating under a heightened state of alert, known as threat condition bravo, that required sailors armed with rifles and wearing body armor to watch all boats approaching the ship.